Windows users will find the library is the PHP 5.2 Windows binaries release.
PHP 5.3 Windows binaries uses the static version of the MCrypt library, no
DLL are needed.

If you linked against libmcrypt 2.4.x or higher, the following additional
block algorithms are supported: CAST, LOKI97, RIJNDAEL, SAFERPLUS,
SERPENT and the following stream ciphers: ENIGMA (crypt), PANAMA, RC4 and
WAKE. With libmcrypt 2.4.x or higher another cipher mode is also
available; nOFB.

User Contributed Notes 5 notes

Both mcrypt and libmcrypt are available through the linked website. You simply have to click the "Browse all files" or similar link once on the "development site" and not just look for the default Sourceforge download button.